It happens everywhere online. YOU need to report them when you see them. Quora can't block the hundreds of thousands that show up. You are their eyes, report when you see them, report spam, report insincere, report harassment, report the users. read more
Nigeria got a headstart in the business. As Quora User pointed out, the snail mail scams started out in Nigeria in the 1990s, enabling Nigerian criminals to build a wealth of experience in the field. There is a low barrier to entry. All you need to get an apprenticeship in the business is some education and a willingness to work. read more
Scam clients want to get the job done without paying you. Also, it ruins the market if there are many workers who can do jobs for free. If a client really wants to test you, there is a way. read more